1. Calm communication: Find a suitable time to have a calm and honest conversation with your mother. Express the situation you have observed and explain your discomfort and concerns about it, try to maintain a calm tone, and avoid blaming.
2. Understanding the reasons: In communication, try to understand the reasons behind the communication between the mother and the man. Perhaps out of friendship, seeking comfort, or other legitimate needs. Understanding her true thoughts and feelings can help you more accurately assess the situation and find solutions.
3. Setting boundaries together: If a mother's behavior indeed exceeds the ethical boundaries of the family, discuss with her and set reasonable social boundaries. Emphasize the importance of family and the responsibility to maintain family harmony, and jointly develop strategies to avoid similar situations from happening again. At the same time, you can also consider sharing your concerns with your father or other family members to jointly solve the problem.